code: def check_classification_targets(y):
      """Ensure that target y is of a non-regression type.
  
      Only the following target types (as defined in type_of_target) are allowed:
          'binary', 'multiclass', 'multiclass-multioutput',
          'multilabel-indicator', 'multilabel-sequences'
  
      Parameters
      ----------
      y : array-like
          Target values.
      """
      y_type = type_of_target(y, input_name="y")
      if y_type not in [
          "binary",
          "multiclass",
          "multiclass-multioutput",
          "multilabel-indicator",
          "multilabel-sequences",
      ]:
          raise ValueError(
              f"Unknown label type: {y_type}. Maybe you are trying to fit a "
              "classifier, which expects discrete classes on a "
              "regression target with continuous values."
          )
  
file_path: catboost/contrib/python/scikit-learn/py3/sklearn/utils/multiclass.py
imports: import warnings
  from collections.abc import Sequence
  from itertools import chain
  import numpy
  from scipy.sparse import issparse
  from ..utils._array_api import get_namespace
  from ..utils.fixes import VisibleDeprecationWarning
  from .validation import _assert_all_finite, check_array
label_desc: Use image node_id 6 for calling a global function with example usage: check_classification_targets(y) without return types